Chemical and biological studies of several radioactive (67Ga, 99mTc, 99Tc, 111In) and non-radioactive (69,71Ga, 113,115In) isotopes of metal ions will be undertaken with functionalized 3-hydroxy-4-pyridinone and hydroxyacylfuran ligands. Because Ga, Tc, and In are all widely used in diagnostic nucelar medicine, the properties of the neutral, water- soluble complexes, both in vivo and in vitro, will be studied and used to design new radioagents. The ligands are chosen for the wide variety of substituents that can be attached, thereby providing some ability to alter their biodistributions as metal complexes. In-vivo biodistributions will be determined in mice. In-vitro properties of the complexes will be studied by octanol-water partitioning, stability-constant determination, and conventional spectroscopies.